Over the years, technology has been developed for transmitting data over the air using an audio signal from a speaker. For example, Spot411 Technologies provides an iPhone application (app) for NBC Universal and 20th Century Fox that tap into DVD or Blu-ray discs to augment viewing. The app uses the microphone on the iPhone or a laptop, to “hear” the audio signal from the movie being played, then responds with pop-ups about the movie. It also intersects with Facebook and Twitter for movie chats. The app makes the DVD part of a networked experience. Universal's Pocket Blu app is just for the iPhone and enables the iphone to act as a remote control for the movie if when played on a Blu-ray player (it currently doesn't work with traditional DVDs or computers) and plays trailers for upcoming movies. Using the internal microphones of the device, 20th Century Fox's FoxPop app listens and synchs up with the film, and then delivers random facts, trivia and behind-the-scenes details that pop up for the viewer at specific points throughout the film. The app can let a user leave a message for a friend who might watch the movie in the future.
Another example is ShopKick's iPhone application that takes advantage of a smart phone's microphone to bring location-sensing indoors, where GPS won't work, for location-based shopping. Beacons smaller than a person's hand fixed to a store's ceiling beam out an inaudible ultrasound signal at a frequency that can be picked up by a cell phone's microphone but not by human ears. The app decodes the signal and contacts ShopKick's database to determine where the user is, and to retrieve some sort of reward for the user.
Neilson offers a service where data transmission via audio signals is used for video on demand reporting. A video on demand (VOD) Audience Measurement service enables content providers to insert a digital audio watermark into VOD content which is audible to Nielsen meters in homes.
Neilson also has personal meters, called “Go Meters,” that capture out-of-home viewing by collecting audio signatures. One device places metering technology in cell phones and the other is a customized meter that resembles an MP3 player. The Meters recognize when a show is playing, based on signals hidden in the audio. One method, called psychoacoustic encoding, injects a digital time stamp and program title—or “active signature”—into the audio tracks of TV shows as they are broadcast. Another technique, called passive signatures, creates a kind of audio fingerprint for TV shows; a split-second sample of audio is digitized, creating a unique signature, which also can be recognized by metering equipment.
The psychoacoustic encoding method relies on digital signals embedded in the audio of broadcast TV shows. These signals—which last for a fraction of a second—are slipped into the audio tracks of TV shows approximately every 2.5 seconds, except for periods of sustained silence. If heard, the encoded signals would be a crrrkkkkk kind of sound. While the codes themselves can be heard by the human ear, they are inserted into audio at points where they are imperceptible. TV networks and broadcasters use equipment called a NAVE (Nielsen Audio Video Encoder) to “burp” these signature codes into the program audio, which are picked up by devices installed in 40,000 viewer's homes—the company's statistical sample base. Called NP (Active/Passive) monitors, these cable-box-sized gadgets tie into the audio output of a TV or home theater system and actively decode and store the psychoacoustic signals.
Despite these advances in data transmission via audio, current technology has limitations that hamper widespread adoption. For example Spot411 works only with Blu-ray or DVDs (not broadcasts) and must use an audio signature of a movie to identify which movies is being played. The app must also first be synched with the movie.
Shopkick requires additional hardware—a separate speaker, to produce the acoustic signal, and determine the presence of the device running the Shopkick application. There is no transmission of any other audio signal besides the inaudible Shopkick signal.
The Neilson system is used to determine when a show is really viewed, vs. the time of its scheduled broadcast; the codes circumvent the problem of time-shifted viewing, because the audio burps also show up on recorded programs when played from a DVR hard drive or VCR tape. The signatures, however, are only used to ID broadcast programs from which the signatures were derived.
In addition, many prior art solutions are based on frequency shift keying (FSK) for modulation/demodulation, which has had limitations in an acoustic communications environment.
Accordingly, it would be desirable to provide an improved over air acoustic data communication method and system.